Abstract
CO(2) electroreduction (CO(2)RR) is an important solution for converting inert CO(2) into high value-added fuels and chemicals under mild conditions. The decisive factor lies in the rational design and preparation of cost-effective and high-performance electrocatalysts. Herein, we first prepare a novel f-SWNTs-650 catalyst via a facile partial thermal atomization strategy, where the residual Ni particles in single-walled carbon nanotubes (SWNTs) are partially converted into atomically dispersed NiN(4) species. CO(2)RR results show that the competitive evolution hydrogen reaction (HER) predominates on pristine SWNTs, while f-SWNTs-650 switches the CO(2) reduction product to CO, achieving a CO faradaic efficiency (FE(CO)) of 97.9% and a CO partial current density (j (CO)) of -15.6 mA cm(-2) at -0.92 V vs. RHE. Moreover, FE(CO) is higher than 95% and j (CO) remains at -10.0 mA cm(-2) at -0.82 V vs. RHE after 48 h potentiostatic electrolysis. Combined with systematic characterization and density functional theory (DFT) calculations, the superior catalytic performance of f-SWNTs-650 is attributed to the synergistic effect between the NiN(4) sites and adjacent Ni NPs, that is, Ni NPs inject electrons into NiN(4) sites to form electron-enriched Ni centers and reduce the energy barrier for CO(2) activation to generate the rate-limiting *COOH intermediate, thus implementing the efficient electroreduction of CO(2).